In communication networks where media is not shared among devices on the network, communications having various priorities conveniently can be handled by providing up to one queue per priority, regardless of the devices designated to receive the communications. Shared media protocols, on the other hand, including those operating under common IEEE standards generally known as 802.11 and 802.15.3, must allow sharing of media amongst devices. This can complicate the ability to share the media by priority, because the sharing is not just by multiple queues, but by multiple queues in each of the separate nodes in the network.
In response to the need to prioritize the sharing of media, the 802.11e standard utilizes various mechanisms such as prioritized carrier sense multiple access/collision avoidance (“CSMA/CA”). While the 802.15.3 standard provides reservation based QoS, it does not directly provide support for QoS based on packet by packet priorities.
The 802.15.3 standard is just one example of a variety of time division multiple access (“TDMA”) protocols. TDMA protocols provide for sharing a single communication channel among simultaneous users of the channel by dividing the channel into time slots. When a device communicates in a network operating in accordance with TDMA, the device is assigned a specific time slot on the channel. By allowing several devices to use different time slots on a single channel, a network using a TDMA protocol can provide an ability to serve multiple devices with a limited number of channels.
The 802.15.3 standard supports the transmission of asynchronous traffic and/or isochronous traffic based on reservations from applications which identify stream types to a MAC (“media access control”). The MAC can allocate different time slots in a stream for devices in the network using the TDMA protocol to send and receive packets. Allocation of different types of streams can be requested in advance from the MAC. Nevertheless, many application programs and protocols do not support the explicit identification of streams. Also, most existing applications do not typically make bandwidth reservations in advance.
As suggested above, the 802.11e standard can support transmitting frames comprising a communication based on priorities. Applications are being developed that can tag packets with priorities. Consequently, support for transmitting frames based on priorities while utilizing TDMA protocols such as 802.15.3 is desired.